Circular surgical stapler with mating anvil and shell assembly

ABSTRACT

A surgical stapler comprising a handle assembly, an elongated body portion extending distally from the handle assembly, and a head portion disposed adjacent a distal portion of the elongated body portion and including an anvil assembly and a shell assembly. The anvil assembly is movable in relation to the shell assembly between spaced and approximated positions. The anvil assembly has an anvil head and a plurality of projections extending proximally of the anvil head, the projections engageable with a portion of the shell assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/582,064, filed on Oct. 20, 2009 now U.S. Pat. No. 8,231,042, whichclaims the benefit of, and priority to, U.S. Provisional PatentApplication Ser. No. 61/111,759, filed on Nov. 6, 2008, the entirecontent of each of the applications identified above being incorporatedby reference herein.

BACKGROUND

1. Technical Field

The present disclosure relates generally to surgical stapling devicesfor applying surgical fasteners to body tissue. More particularly, thepresent disclosure relates to surgical stapling devices suitable forperforming circular anastomosis and/or treating the internal walls ofhollow body organs, e.g., hemorrhoidal tissue.

2. Background of Related Art

Anastomosis is the surgical joining of separate hollow organ sections.Typically, an anastomosis procedure follows surgery in which a diseasedor defective section of hollow tissue is removed and the remaining endsections are to be joined. Depending on the desired anastomosisprocedure, the end sections may be joined by either circular, end-to-endor side-to-side organ reconstruction methods.

In a circular anastomosis procedure, the two ends of the organ sectionsare joined by means of a stapling instrument which drives a circulararray of staples through the end section of each organ section andsimultaneously cores any tissue interior of the driven circular array ofstaples to free the tubular passage.

Examples of instruments for performing circular anastomosis of holloworgans are described in U.S. Pat. Nos. 7,303,106, 6,053,390, 5,588,579,5,119,983, 5,005,749, 4,646,745, 4,576,167, and 4,473,077. Typically,these instruments include an elongated shaft having a handle portion ata proximal end to actuate the instrument and a staple holding componentdisposed at a distal end. An anvil assembly including an anvil centerrod with attached anvil head is mounted to the distal end of theinstrument adjacent the staple holding component. Opposed end portionsof tissue of the hollow organ(s) to be stapled are clamped between theanvil head and the staple holding component as these components areapproximated. The clamped tissue is stapled by driving one or morestaples from the staple holding component through the staple slots sothat the ends of the staples pass through the tissue and are deformed byanvil pockets of the anvil head. An annular knife is concurrentlyadvanced to core tissue with the hollow organ to free a tubular passagewithin the organ.

Besides anastomosis of hollow organs, surgical stapling devices forperforming circular anastomosis have been used to treat internalhemorrhoids in the rectum. Hemorrhoids are masses of tissue in the anuscontaining enlarged blood vessels. Internal hemorrhoids are inside theanal canal; external hemorrhoids lie outside the anal canal. Inhemorrhoidectomy, the hemorrhoids are removed. Stapled hemorrhoidopexyis a surgical procedure in which the stapling device is used to removetissue just above the hemorrhoids in order to pull the hemorrhoids backup inside the rectum and reduce the symptoms. The staples interrupt theblood flow of the superior hemorrhoidal arterial branches, cutting offthe blood supply to the tissue, thus causing the hemorrhoids to shrink.

During the use of a circular stapling device for hemorrhoid treatment,the anvil head and the staple holding component of the device areinserted through and into the rectum with the anvil head and thestapling holding component in an open or unapproximated position.Thereafter, a purse string suture is used to pull the internalhemorrhoidal tissue and/or mucosal tissue toward the anvil rod. Next,the anvil head and the staple holding component are approximated toclamp the hemorrhoidal tissue and/or mucosal tissue between the anvilhead and the staple holding component. The stapling device is fired toremove the hemorrhoidal tissue and/or mucosal tissue and staple the cuttissue.

Various techniques of using the purse string suture to pull the internalhemorrhoidal tissue towards the center rod are known in the art. Forexample, U.S. Pat. No. 6,102,271 to Longo, et al., discusses graspingand pulling the purse string proximally through the use of a separatedevice that is inserted into the stapling device.

International Application Publication No. WO 2008/107918 to Rebuffat, etal., discloses placing the purse string suture into one or more annulargrooves formed in the anvil center rod.

It would be desirable, therefore, to provide a surgical stapling deviceincluding structure that is configured and dimensioned to enhancealignment between the staple holding component and anvil head.

It certain procedures, it may be desirable to provide a longer centerrod (anvil shaft) of the anvil assembly. Therefore, such enhancedalignment and cooperation between the stapling component and anvil wouldbe advantageous.

SUMMARY

In one aspect of the present disclosure, a surgical stapling device isdisclosed that includes a surgical stapler comprising a handle assembly,an elongated body portion extending distally from the handle assembly,and a head portion disposed adjacent a distal portion of the elongatedbody portion and including an anvil assembly and a shell assembly, theanvil assembly being movable in relation to the shell assembly betweenspaced and approximated positions. The anvil assembly has an anvil headand a plurality of projections extending proximally of the anvil head,the projections engageable with a portion of the shell assembly.

Preferably, the shell assembly includes a plurality of openings aligningwith respective projections of the anvil assembly. In a preferredembodiment, the projections are frictionally received in a respectiveopening. The projections can have a tapered end.

In one embodiment, the anvil assembly includes an anvil shaft extendingproximally of the anvil head and removably mountable to an anvilretainer of the stapler.

In one embodiment, the plurality of projections are substantiallyequidistantly radially spaced. In one embodiment, the projections extendsubstantially parallel with the anvil shaft.

In one embodiment, the anvil assembly includes a center rod and an anvilhead, the center rod including at least one aperture extendingtransversely therethrough and the aperture configured and dimensioned toreceive a flexible member such that the flexible member extendstransversely through the center rod.

In another aspect of the present disclosure an anvil assembly isprovided comprising an anvil head and a center rod extending from theanvil head. The center rod includes a first annular engagement memberconfigured to removably engage an anvil retainer of a surgical staplingdevice. A plurality of projections extend proximally of the anvil headfor engagement with a plurality of openings in the surgical staplingdevice.

The center rod may include a plurality of apertures extendingtransversely therethrough, the apertures configured and dimensioned toreceive a suture therethrough.

In one embodiment, the plurality of projections are substantiallyequidistantly radially spaced. In one embodiment, the plurality ofprojections comprises first and second projections spaced approximately180 degrees apart.

The center rod preferably includes a plurality of splines for alignmentof the center rod with a shell assembly of a surgical stapling devicewith the projections preferably terminating distally of the splines.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure are described herein belowwith reference to the drawings, wherein:

FIG. 1 is a side, perspective view of a surgical stapling deviceincluding an anvil assembly and a shell assembly shown in anun-approximated position, in accordance with the principles of thepresent disclosure;

FIG. 2 is an exploded view of a portion of the surgical stapling deviceof FIG. 1, including the handle assembly;

FIG. 3 is a side perspective view of the anvil assembly and the shellassembly of the surgical stapling device;

FIG. 4 is an exploded view of the shell assembly;

FIG. 5 is a longitudinal cross-sectional view of one embodiment of ananvil retainer for use with the surgical stapling device;

FIG. 6 is a longitudinal cross-sectional view of the surgical staplingdevice of FIG. 1 incorporating the anvil retainer shown in FIG. 5;

FIG. 7 is a side view of a connector for use with the anvil retainershown in FIG. 5 to operatively connect the anvil retainer to a drivescrew;

FIGS. 8 and 9 are side perspective views of the anvil assembly;

FIG. 10 is a side perspective view of the anvil assembly with partsseparated;

FIG. 11 is an enlarged view of the area of detail indicated in FIG. 10illustrating a tissue contacting surface of the anvil assembly;

FIG. 12 is a side view of an alternative embodiment of the instrument ofthe present disclosure having an anvil assembly with alignment pins;

FIG. 12A is a perspective view illustrating the pins of anvil assemblyof FIG. 12 and the shell assembly with openings to receive the pins;

FIGS. 12B and 12C are partial, longitudinal cross-sectional views of theanvil assembly respectively illustrating the anvil assembly before andafter deformation to secure the anvil within the anvil head;

FIG. 13 is a longitudinal cross-sectional view of the surgical staplingdevice of FIG. 1 with the anvil in the un-approximated position;

FIG. 14 is an enlarged view of the area of detail indicated in FIG. 13illustrating a distal portion of the surgical stapling device in theun-approximated position;

FIG. 15 is an enlarged view of the area of detail indicated in FIG. 14illustrating the anvil head component of the anvil assembly;

FIG. 16 is a side, perspective view of the anvil assembly according toan alternative embodiment of the present disclosure;

FIG. 16A is cross-sectional view showing engagement of the anvilassembly of FIG. 16 with an alternative embodiment of the shell boss ofthe shell assembly;

FIG. 17 is a top view of an exemplary slot formed in the shell assemblythat is configured and dimensioned to receive a surgical fastener;

FIGS. 18 and 19 are side views of a screw stop component of the surgicalstapling device;

FIG. 20 is a side perspective view of the screw stop shown in FIGS. 18and 19;

FIGS. 21A and 21B are side views illustrating washers for use with thescrew stop shown in FIGS. 18 and 19;

FIG. 22 is a side, perspective view of a slide member component of anindicator mechanism of the surgical stapling device;

FIG. 23 is an enlarged view of the area of detail indicated in FIG. 13illustrating the indicator mechanism and drive screw in theunapproximated position;

FIG. 24 is a top, perspective view of a lockout member for use with thesurgical stapling device to prevent inadvertent firing;

FIG. 25 is an enlarged view of the area of detail indicated in FIG. 2illustrating an abutment member component of a tactile indicatormechanism;

FIG. 26 is a side, perspective view of the abutment member illustratedin FIG. 25;

FIG. 27 is a front, perspective view of an anoscope kit including anobturator, an anoscope, and a port for use with the surgical staplingdevice;

FIG. 28 is a side, perspective view of the assembled anoscope kit;

FIG. 29 is a longitudinal cross-sectional view of the assembled anoscopekit positioned within a patient;

FIG. 30 is a longitudinal cross-sectional view of the anoscope kitpositioned within a patient following removal of the obturator andapplication of a purse string suture;

FIGS. 31-33 are proximal end views of the anoscope kit positioned withina patient following removal of the obturator illustrating a pursestringing procedure in which a suture is attached to target tissue;

FIG. 34 is a longitudinal cross-sectional view of the port component ofthe anoscope kit and the anvil assembly component of the surgicalstapling device positioned within a patient following purse stringingand illustrating attachment of the purse string suture to the anvilassembly;

FIG. 35 is a longitudinal cross-sectional view of the port component ofthe anoscope kit and the anvil assembly component of the surgicalstapling device positioned within a patient following purse stringingand attachment of the anvil assembly to the anvil retainer of thesurgical stapling instrument;

FIG. 36 is a longitudinal cross-sectional view illustrating the distalend of the surgical stapling device positioned within the port componentof the anoscope kit following approximation of the anvil assembly andthe shell assembly; and

FIG. 37 is a longitudinal cross-sectional view of the surgical staplingdevice following removal of the surgical stapling device and attachedanvil assembly from the port component of the anoscope kit, andillustrating the removed target tissue within the shell assembly of thestapling device.

DETAILED DESCRIPTION

The presently disclosed surgical stapling device will now be describedin detail with reference to the drawings in which like referencenumerals designate identical or corresponding elements in each of theseveral views. Throughout this description, the term “proximal” willrefer to the portion of the surgical stapling device, or componentthereof, that is closer to the clinician during proper use, and the term“distal” will refer to the portion of the surgical stapling device, orcomponent thereof, that is further from the clinician during proper use.Additionally, the terms “hemorrhoidal tissue” and the like will refer tohemorrhoidal tissue, as well as tissue positioned adjacent tohemorrhoidal tissue, including mucosal tissue. The presently disclosedsurgical stapling device is particularly suited for surgical hemorrhoidprocedures, although it can be used in other procedures. The term“hemorrhoid procedure” should be understood to encompass surgicalhemorrhoidectomies, hemorrhoidopexies, mucosectomies, procedures for thetreatment of colon prolapse, and all such related procedures.

FIG. 1 illustrates the presently disclosed surgical stapling device,which is referred to generally by the reference numeral 10. Briefly, thesurgical stapling device 10 includes a handle assembly 12, a centralbody portion 14 including an outer tube 14 a, and a distal head portion16. The handle assembly 12 includes a stationary handle 18, a firingtrigger 20, a rotatable approximation knob 22, and an indicator 24positioned on the stationary handle 18, which provides the clinicianwith information regarding whether or not the stapling device 10 isready for firing, i.e. the anvil has been satisfactorily approximated.It is envisioned that the stationary handle 18 may be formed fromindividual handle sections 19A, 19B (FIG. 2) that together define ahousing for the internal components of handle assembly 12. As shown inFIG. 1, the stationary handle 18 and the trigger 20 may respectivelyinclude cushioned and slip-resistant portions 18A, 20A to facilitategripping and manipulation of the handle assembly 12 by the clinicianduring the surgical procedure. A trigger lock 26 is pivotally mounted tothe handle assembly 12, and is selectively repositionable by theclinician to prevent inadvertent firing of the stapling device 10. Thestructure and operation of the trigger lock 26 will be discussed indetail herein below.

The head portion 16 of the surgical stapling device 10 includes an anvilassembly 30 and a shell assembly 31. Except where otherwise noted, thecomponents of the stapling device 10 are generally formed fromthermoplastics including polycarbonates, and metals including stainlesssteel and aluminum. The particular material selected to form aparticular component will depend upon the strength requirements of theparticular component. For example, the anvil assembly 30 may be formedfrom a metal such as stainless steel, whereas portions of handleassembly 12 may be formed from thermoplastic such as a polycarbonate.Alternately, other materials having the requisite strength requirementswhich are suitable for surgical use may be used to form the componentsof the stapling device 10.

The head portion 16 is repositionable between an un-approximatedposition (FIGS. 1, 13), wherein the anvil assembly 30 is spaced adistance from the shell assembly 31, and an approximated position,wherein the anvil assembly 30 abuts the shell assembly (FIG. 36). Toadvance and retract the anvil assembly 30 relative to the shell assembly31, and thus repositioning of the head portion 16 between theun-approximated and approximated positions, the stapling device 10further includes an approximation mechanism.

Referring now to FIGS. 1-4, the approximation mechanism includesapproximation knob 22, a drive screw 32, a rotatable sleeve 33, and ananvil retainer 38 that is configured and dimensioned to securely receivethe anvil assembly 30 in a manner that will be described below.

The rotatable sleeve 33 (FIG. 2) includes a substantially cylindricalhollow body portion 40, as well as a substantially cylindrical collar42, which together define a central bore 33A. The collar 42 includesstructure that is configured and dimensioned for engagement withcorresponding structure formed on the stationary handle 18 (FIG. 1). Forexample, in the embodiment illustrated in FIG. 2, the collar 42 includesan annular groove 44 formed thereabout that is configured anddimensioned to receive an inwardly extending flange 46 that is formed onan inner wall of the stationary handle 18. Engagement between the groove44 and the flange 46 inhibits relative axial movement between the sleeve33 and the stationary handle 18, while permitting rotation of the sleeve33 relative to the stationary handle 18.

A proximal end of the body portion 40 of the rotatable sleeve 33 extendsthrough an opening 18 b (FIG. 2) located at a proximal end of thestationary handle 18. The body portion 40 also includes one or more ribs48 that are positioned on the outer surface thereof that are positionedwithin a pair of internal slots 49A that are formed in the approximationknob 22. Engagement between the ribs 48 and the slots 49A inhibitsrelative rotation between the sleeve 33 and the approximation knob 22such that rotation of the approximation knob 22 causes correspondingrotation of the sleeve 33.

The drive screw 32 is slidably positioned within the central bore 33A ofthe rotatable sleeve 33. The screw 32 includes a proximal portion with ahelical channel 50 (FIG. 2) that engages with a pin 52 that extendsradially through the collar 42 of the sleeve 33. Since the sleeve 33 isaxially fixed with respect to the stationary handle 18, rotation of thesleeve 33 about the screw 32 causes the pin 52 to move along the channel50 of the screw 32 to effect axial movement of the screw 32 within thestationary handle 18. At a distal end, the screw 32 further includesaxial grooves 54 and a throughbore 34 that receives a pin 64 (FIG. 2).Although the structure identified by reference numerals 52 and 64 isreferred to, and illustrated as, a pin, it should be understood that anystructure capable of achieving the disclosed interactions may beemployed, e.g., screws, rivets, or the like.

As seen in FIG. 4, the anvil retainer 38 has a proximal end 38A with athroughbore 267 formed therein. The throughbore 267 receives pin 64(FIG. 2). The anvil retainer 38 is connected to the screw 32 bypositioning the proximal end 38A of the anvil retainer 38 within theaxial groove 54 of the screw 32, and the pin 64 within the throughbore34 of the screw 32 and the throughbore 267 of the anvil retainer 38. Theanvil retainer 38 also includes an annular recess to engage thecorresponding annular protrusion 280 (FIGS. 3, 10) on the anvil assembly30, and axial grooves 268 (FIG. 3) that engage a corresponding number ofsplines 270 formed on a center rod 154 of the anvil assembly 30. Theaxial grooves 268 separate the anvil retainer 38 into flexible fingers272. Additional detail regarding engagement of the anvil retainer 38 andthe anvil assembly 30 are provided below. It should be appreciated thatwhile the anvil retainer 38 is illustrated as including three fingers272, and the center rod 154 is illustrated as including three splines270, the fingers 272 and the splines 270 may be present in greater orfewer numbers in alternative embodiments of the present disclosure.

With reference to FIGS. 5-7, in an alternative embodiment of the presentdisclosure, the stapling device 10 includes an anvil retainer referredto generally by reference character 36A (FIG. 5). The anvil retainer 36Ais substantially similar to the anvil retainer 38 described above, andaccordingly, will only be discussed with respect to any differencestherefrom.

The anvil retainer 36A has respective proximal and distal ends 36B, 36C,and includes a body 36D defining an elongated bore 36E. The proximal end36B of the body 36D includes a longitudinal slot 36F, as well as a pairof transverse throughbores 36G, and the distal end 36C of the body 36Dincludes segmented, flexible arms 36H. Although illustrated as includingthree segmented arms 36G, the segmented arms may be present in greateror fewer numbers in additional embodiments of the anvil retainer 36A.Each arm 36G includes an inner retention surface 361 that is configuredand dimensioned to engage the anvil assembly 30 (FIGS. 1, 3) to inhibitrelative movement therebetween. Specifically, the inner retentionsurface 361 engages a corresponding annular protrusion 280 (FIGS. 3, 10)of anvil assembly 30.

The anvil retainer 36A is configured and dimensioned for operativeconnection to the drive screw 32 (FIG. 6) via a connector 38. Theconnector 38 includes a central body 38A with a proximal extension 38Bfor engagement with the distal end of the drive screw 32, e.g., viapositioning within a slot (not shown) formed in the distal end of thedrive screw 32 having a corresponding configuration and dimensions, anda distal extension 38C. The proximal extension 38B and the distal end ofdrive screw 32 each define a transverse throughbore (not shown) forreceiving a pin, rivet, screw or the like 39A (FIG. 6) in order tofixedly secure the connector 38 to the distal end of the drive screw 32.The distal extension 38C is dimensioned to be received within thelongitudinal slot 36F (FIG. 5) formed in the proximal end 36B of thebody 36D of the anvil retainer 36A. The distal extension 38C of theconnector 38 includes a pair of spaced throughbores (not shown) whichalign with the throughbores 36G formed in the anvil retainer 36A, toreceive pins, screws, rivets or the like 39B (FIG. 6) to fixedly securethe anvil retainer 36A to the proximal extension 38B of the connector38. Although the anvil retainer 36A and the connector 38 are disclosedas being attached via pins, screws, rivets or the like 39A, 39B, otherknown fastening techniques are also envisioned, including but notlimited to welding, crimping, and interlocking structure.

Referring again to FIGS. 1-4, during use of the stapling device 10,rotation of the approximation knob 22 (FIGS. 1, 2) causes correspondingrotation of the rotatable sleeve 33 about the proximal end of screw 32,which thereby moves the pin 52 (FIG. 2) through the helical channel 50.Since the sleeve 33 is axially fixed to the stationary handle 18,proximal movement of the pin 52 through the helical channel 50 causesretraction of the screw 32 within the stationary handle 18, and distalmovement of the pin 52 through the helical channel 50 causes advancementof the screw 32 within the stationary handle 18. Engagement of the anvilassembly 30 and the anvil retainer 38 (FIG. 1) is such that rotation ofthe approximation knob 22 effectuates movement of the anvil assembly 30in relation to the shell assembly 31 to thereby move the head portion 16(FIG. 1) of the surgical stapling device 10 between the unapproximated(spaced) and approximated positions.

With particular reference to FIGS. 1 and 2, the stapling device 10further includes a firing mechanism to facilitate the ejection offasteners, e.g., staples 230 (FIG. 14). Specifically, the firingmechanism includes the aforementioned firing trigger 20, a firing link72, and an elongated pusher link 74 (see also FIG. 4). The trigger 20includes a body portion 76 (FIG. 2), and a trigger cover 80. The bodyportion 76 of the trigger 20 is pivotally connected to a coupling member86 (FIG. 2) that is secured to the proximal end of the pusher link 74 bya pivot pin 84. In an alternative embodiment of the disclosure, however,it is envisioned that the coupling member 86 may be fixedly attached to,e.g., integrally formed with, the pusher link 74.

The firing link 72 has a first end that is pivotally secured to the bodyportion 76 of the trigger 20, e.g., via a pivot member 87, and a secondend that is pivotally secured within a vertical slot 82 (FIGS. 2, 25)that is formed between the stationary handle sections 19A, 19B of thestationary handle 18, e.g., via a pivot member 79. The pivot member 79is configured and dimensioned for vertical movement within the slot 82,and is biased downwardly towards the bottom of the slot 82 by a spring82A that is supported within the stationary handle 18.

The body portion 76 of the trigger 20 further includes a pair ofabutments 89, 91 (FIG. 2) that are positioned to engage an end 26A ofthe trigger lock 26 to prevent actuation of trigger 20 prior toapproximation of device 10.

The coupling member 86 (FIGS. 2, 4), which is positioned at the proximalend of the elongated pusher link 74, includes a flange 104. A spring 106is positioned between an inner wall, or abutment, within the stationaryhandle 18 and flange 104 to thereby bias the pusher link 74 proximallyto a retracted, non-fired position. The coupling member 86 includes apair of wings 108 extending radially outward therefrom for slidingengagement with a channel 111 (FIG. 2) that is formed along the internalwalls of the stationary handle 18. Engagement of the wings 108 with thechannel 111 maintains proper alignment of the pusher link 74 within thestationary handle 18 during firing of the stapling device 10.

The pusher link 74 is positioned within the outer tube 14 a of the bodyportion 14, and includes structure that is configured and dimensioned tofacilitate secure engagement with a pusher back 186 (FIG. 4). The pusherback 186 forms part of shell assembly 31 (FIG. 1), and will be discussedin greater detail below. In the illustrated embodiment, for example, thepusher link 74 includes a pair of engagement fingers 110 (FIG. 4) at adistal end thereof that are configured and dimensioned for secureengagement with members 220 formed in the proximal end of the pusherback 186, e.g., in interlocking relation. Additionally, the pusher link74 defines a hollow channel 75 extending therethrough to slidablyreceive the assembled approximation mechanism.

Upon actuation of the firing trigger 20, the firing trigger 20 ispivoted about the pivot member 84 which causes the firing link 72 tomove proximally until the pivot member 79 engages an abutment surfaceformed on a screw stop 306 (FIGS. 2, 13,14). The screw stop 306 isconnected to the screw 32 in a manner inhibiting relative axial movementbetween the screw stop 306 and the screw 32 that will be discussedbelow. Distal movement of the firing trigger 20 causes correspondingdistal movement of the pusher link 74 (FIGS. 2, 4) against the biasapplied by the spring 106. Since the distal end of the pusher link 74 isconnected to the pusher back 186, actuation of the firing trigger 20effectuates distal advancement of the pusher back 186 within the shellassembly 31 to eject the fasteners 230 from the shell assembly 31.

Referring now to FIGS. 8-15, the anvil assembly 30 will be discussed.The anvil assembly 30 includes an anvil head assembly 120 and an anvilcenter rod or anvil shaft 152. The anvil head assembly 120 includes apost 122 (FIG. 10), an anvil head 124, a cutting ring 128, and an anvil129.

The anvil head 124 includes a centrally-positioned bore that receivesthe post 122, details of which are provided below, as well as vent holes125 (FIG. 8), a bulbous member 126, and an outer annular recess 136(FIG. 10) to receive the anvil 129. The bulbous member 126 is configuredand dimensioned to allow smooth passage of the anvil assembly 30 throughan opening in the patient's tissue, e.g., the patient's anus.

As seen in FIGS. 10 and 15, the cutting ring 128 is an annular memberthat is positioned within an inner annular recess 135 formed in anvilhead 124. The cutting ring 128 includes respective proximal and distalends 128A, 128B (FIG. 15), and defines an inner proximally facingannular shoulder 128C, as well as an outer proximally facing annularsurface 128D. The inner annular shoulder 128C and the annular surface128D of the cutting ring 128 engage the anvil head 124 such that thecutting ring is retained within the recess 135. For example, as seen inFIG. 15, the anvil head 124 may include an inner wall with an outwardlyextending finger 131A that engages the inner annular shoulder 128C, andan outer wall with an inwardly extending finger 131B that engages theouter annular surface 128D. During use of the stapling device 10, uponfiring, the cutting ring 128 is penetrated by the knife 188 (FIG. 4).

Anvil 129 includes structure that is configured and dimensioned forengagement with corresponding structure formed in the anvil head 124 tofacilitate proper alignment between the anvil 129 and the outer annularrecess 136 formed in the anvil head 124. In the illustrated embodiment,for example, the anvil 129 includes a tab 129A (FIG. 12B) extendingradially outwardly therefrom for engagement with a cutout 124A formed inthe anvil head 124. It should be appreciated, however, that alternativestructure may be employed to achieve proper alignment between the anvil129 and the anvil head 124.

The anvil 29 is a die-cast member that can be formed from any suitablematerial. Examples of materials suitable for the construction of theanvil 129, as well as the anvil head 124, include, but are not limitedto steel, titanium, magnesium, aluminum, or zinc alloy. It is envisionedthat the anvil 129 and the anvil head 124 may be comprised of the samematerial, or alternatively, that the materials comprising the anvil 129and the anvil head 124 may be different. In one specific embodiment ofthe anvil assembly 30, the anvil 129 is formed from the zinc alloy Zamak#3, which includes at least 95% zinc, aluminum, magnesium, and copper.

The anvil 129 includes a body 250 with a tissue contacting surface 252,and a bottom surface 254. In one embodiment of the anvil 129, the tissuecontacting surface 252 may include a coating 252A, as shown in FIG. 11,that is formed from a suitable biocompatible material. Incorporation ofthe coating 252A may reduce the likelihood that the patient's tissuewill stick, or adhere, to the anvil 129, and/or may enable the anvil 129to be formed from materials that could not otherwise be included in theconstruction thereof due to bio-incompatibility, e.g., theaforementioned zinc alloy Zamak #3. In one particular embodiment of theanvil 129, the coating 252A may include Teflon, although the use ofother materials is contemplated.

As seen in FIG. 11, the tissue contacting surface 252 of the anvil 129includes a plurality of pockets 255 that are arranged into a pluralityof annular rows to receive and deform corresponding annular rows ofstaples. In the embodiment of the anvil 129 illustrated in FIGS. 10 and11, for example, the anvil 129 includes two annular rows of pockets 255.It should be appreciated, however, that the rows of pockets 255 may bepresent in either greater or fewer numbers in alternative embodiments ofthe anvil 129.

The pockets 255 include a pair of cavities 256 that are connected by alinear section 257 including a pair of forming surfaces 258. Thecavities 256 define an outer rim 256A, and slope inwardly therefrom,i.e., away from the tissue contacting surface 252. The cavities 256 areconfigured and dimensioned to urge the legs of the fasteners 230 intothe linear section 257, and more specifically, into contact with theforming surfaces 258. The presence of the cavities 256 relaxes thetolerances of the stapling device 10 by reducing the precision withwhich the fasteners 230 need to be ejected from the shell assembly 31(FIG. 1) in order to facilitate desired contact between the legs of thefasteners 230 and the forming surfaces 258. By reducing such tolerances,the likelihood that an ejected fastener 230 will contact the formingsurfaces 258 as desired for staple formation is increased, therebydecreasing the costs associated with manufacture of the device.

In one embodiment of the anvil 129, it is envisioned that the cavities256 may be substantially spherical in configuration, as best shown inFIG. 11, although alternative configurations are not beyond the scope ofthe present disclosure. The substantially spherical configurationincreases the surface area of the cavities 256 available for contactwith the legs of the fasteners 230.

As mentioned above, the cavities 256 are connected by the linear section257. More specifically, at least a portion of the outer rim 256A of eachcavity 256 intersects the linear section 257, e.g., to substantiallylimit any interruption in the movement of the legs of the surgicalfastener 230 from the cavities 256 into contact with the formingsurfaces 258. The linear section 257 defines a length “L” that isdetermined based upon the specific dimensions of the fasteners 230 to beformed. Accordingly, the length “L” of the linear section 257 can bevaried in alternative embodiments of the anvil 129 dependent upon theparticular configuration and dimensions of the fasteners 230 loaded intothe shell assembly 31.

The forming surfaces 258 are arcuate in configuration along the length“L” of the linear section 257, initially curving away from, and thentowards, the tissue contacting surface 252. This curvature promotesredirection and deformation of the legs of the fasteners 230 such thatthe fasteners 230 can achieve a desired formed configuration. In theembodiment of the anvil 129 seen in FIGS. 10 and 11, for example, theforming surfaces 258 are positioned, configured, and dimensioned suchthat the fasteners 230 achieve a standard “B-shaped” configuration. Inalternative embodiments of the anvil 129, however, the position,configuration, and/or dimensions of the forming surfaces 258 can beadjusted to alter the formed configuration of the fasteners 230, e.g.,the forming surfaces 258 may be positioned, configured, and dimensionedsuch that the fasteners 230 achieve a single loop configuration uponformation.

The fastener pockets 255 further include a pair of side walls 259 thatextend from the forming surfaces 258 to the tissue contacting surface252. The side walls 259 are configured and dimensioned to further ensureproper formation of the surgical fasteners 230. For example, it isenvisioned that the side walls 259 may define a substantially planarconfiguration that limits lateral movement of the legs of the surgicalfasteners 230 within the fastener pockets 255, i.e., in the directionindicated by arrow 1. Restricting such movement maintains contactbetween the legs of the fasteners 230 and the forming surfaces 258 untilformation of the fasteners 230 is complete.

As seen in FIGS. 12B and 12C, the anvil 129 further includes an outerstep 129A, and a side wall 129B that is angled towards a longitudinalaxis X-X of the anvil assembly 30 (see also FIG. 9). During assembly,the anvil 129 is positioned within the outer annular recess 136 (seealso FIG. 10) formed in the anvil head 124 such that the outer step 129Acontacts an annular shoulder 124A defined by the anvil head 124.Thereafter, the anvil head 124 is deformed inwardly, e.g., by swaging,towards the longitudinal axis X-X such that an inner surface 136A of theouter annular recess 136 comes into contact with the side wall 129B ofthe anvil 129, as can be seen in the transition between FIGS. 12B and12C. After deformation, the anvil head 124 is positioned flush with thetissue contacting surface 252 of the anvil 129 such that the anvilassembly 30 (FIG. 1) defines a proximal-most surface 120A (FIGS. 12B,12C) that is substantially uniform and substantially planar inconfiguration.

With particular reference to FIGS. 8-10, 13, and 14, the anvil centerrod assembly 152 will be discussed. The anvil center rod assembly 152includes an anvil center rod 154 having a length sufficient to allow theanvil center rod 154 to protrude from an external surface of thepatient's tissue, e.g., from the patient's anus, when properlypositioned during a surgical hemorrhoid procedure. For example, forhemorrhoid surgery use, the anvil center rod 154 may have a length ofabout 13.5 cm (approximately 5.3 inches), although longer and shortercenter rods 154 are not beyond the scope of the present disclosure.Allowing the anvil center rod 154 to protrude from the patient's anusallows for improved visibility of the interface between the anvil centerrod 154 and the anvil retainer 38.

The anvil center rod 154 includes a proximal portion 274 (FIG. 10) witha tapered blunt end 274A, a distal portion 276, and a central portion284 that is positioned therebetween. A distal end of the center rod 154includes a transverse throughbore 160 extending through the centrallongitudinal axis of the center rod 154 that is positioned for alignmentwith a transverse throughbore 162 formed in the post 122 of the anvilhead assembly 120. An attachment member 164, such as a pin, screw,rivet, or the like, is positioned within the throughbores 160, 162 tosecure the post 122 to the center rod 154.

The proximal portion 274 of the center rod 154 includes a trocar 278with a tapered proximal end. Annular protrusion 280, which is configuredand dimensioned for releasable engagement with a corresponding annularrecess 282 (FIG. 14) formed at the distal end of the anvil retainer 38.The annular protrusion 280 defines an outer transverse dimension that isgreater than the inner transverse dimension of the anvil retainer 38.Accordingly, during attachment of the anvil center rod assembly 152 tothe anvil retainer 38 (FIG. 14), proximal advancement of the center rod154 through the anvil retainer 38 causes engagement between the flexiblefingers 272 (FIG. 3) of the anvil retainer 38 and the annular protrusion280. This engagement forces the flexible fingers 272 radially outward,and thereby facilitates engagement of the annular protrusion 280 and theannular recess 282 (FIG. 14). Engagement between the annular protrusion280 and the annular recess 282 inhibits relative longitudinal movementbetween the center rod 154 and the anvil retainer 38 until theapplication of a predetermined force to the anvil assembly 30 in adistal direction when disconnection of the center rod 154 from the anvilretainer 38 is desired.

Referring back to FIGS. 8-10, the central portion 284 of the center rod154 has an outer transverse dimension that is greater than an innertransverse dimension defined by the anvil retainer 38 in order to limitinsertion of the center rod 154 into the anvil retainer 38. That is,engagement of the central portion 284 with the distal end of the anvilretainer 38 prevents continued insertion of the center rod 154 into theanvil retainer 38.

The distal portion 276 of the center rod 154 includes one or moreapertures, e.g., apertures 286A, 286B, 286C, formed therein that arepositioned proximally of the throughbore 160. Although illustrated asincluding three apertures, it should be appreciated that greater orfewer number of apertures may be included in alternative embodiments ofthe center rod 154. Although the apertures are show substantiallyequidistantly spaced, other spacing of the apertures is alsocontemplated. The apertures 286A-286C extend through the center rod 154,and are configured and dimensioned to receive a flexible membertherethrough, such as a length of suture “S” as described below (FIG.34). In the illustrated embodiment, the apertures 286A-286C are spacedlongitudinally along the center rod 154, which allows the clinician tocontrol the amount of tissue drawn into the shell assembly 31.Specifically, by positioning the suture “S” within the proximal-mostaperture 286A, a greater amount of tissue will be drawn into the shellassembly 31 when compared to the amount of tissue that will be drawninto the shell assembly 31 by attaching the suture “S” to thedistal-most aperture 286C.

In one embodiment of the disclosure, it is contemplated that the centerrod 154 may further include a marker such as a ring 287 that ispositioned between the apertures 286A and 286B to signify to a clinicianthat attachment of a suture to the proximal-most aperture will effect alarge tissue bite.

The distal portion 276 of the anvil center rod 154 further includessplines 270 which are configured and dimensioned for slidable engagementwith corresponding axial grooves (not shown) formed in shell assembly 31during approximation of the anvil assembly 30 and the shell assembly 31.Engagement between the splines 270 and the axial grooves of the shellassembly 31 acts to properly align the anvil assembly 30 with the shellassembly 31 such that the fastener anvil pockets 255 formed in thetissue contacting surface 252 of the anvil 129 align with the slots 228(FIG. 4) formed in the fastener guide 192.

In an alternate embodiment shown in FIGS. 16 and 16A, a center rod(anvil shaft) 154′ is disclosed. The center rod 154′ is substantiallysimilar to the center rod 154 described herein, and accordingly, willonly be discussed in detail with respect to any differences therefrom.Components of the center rod 154′ corresponding to the components ofcenter rod 154 are labeled with prime designations. Thus, for example,center rod 154′ has apertures 286A′, 286B′, 286C′, is mounted to headassembly 120′ and has trocar 278′.

The center rod 154′ includes an outer annular member (protrusion) 280′similar to annular protrusion 280 of FIG. 19. To attach the anvilassembly 30′ to the anvil retainer 38, the center rod 154′ (like centerrod 154) is positioned within the anvil retainer 38 (FIGS. 1 and 5), andadvanced proximally such that the annular protrusion 280′ of the centerrod 154′ engages the flexible fingers 272 of the anvil retainer 38. Uponengagement of the annular protrusion 280′ with the flexible fingers 272,the flexible fingers 272 are forced outwardly, thereby facilitatingengagement of the annular protrusion 280′ and the annular recess 282 ofthe anvil retainer 38 to inhibit relative longitudinal movement betweenthe center rod 154′ in the same manner as described above with respectto protrusion 280 of FIG. 10.

Center rod 154′ includes a second raised annular ring or interferencerib 290 configured and dimensioned to enhance frictional engagement ofthe center rod 154′ with the shell assembly 31 (FIG. 1) to furtherenhance stability. To achieve frictional engagement with the shellassembly 31′, the annular member 290′ is configured and dimensioned toengage a raised boss 37 of the shell assembly 31′ when the anvilassembly 30′ is attached to the anvil retainer 38 and approximated. Thisis illustrated in FIG. 16A where the annular member 290′ engages theraised shell boss 37. As shown, the member 290 is positioned proximallyof the suture apertures 286A′, 286B′, 286C, and in the illustratedembodiment is positioned adjacent the proximalmost aperture 286A′. Otherlocations are also contemplated. Note the shell assembly 31′ issubstantially identical to shell 31 described herein except for theraised boss 37 which engages annular member 290 when the anvil shaft154′ is attached to the surgical stapling instrument 10. Thisinterference provides an additional engagement to enhance the stabilityof the anvil assembly when attached to the instrument. Anvil shaft 154′also includes a plurality of machined splines 270′ for alignment withgrooves of the shell assembly 31′ in the same manner as splines 27described above. Alternatively, the splines can be overmolded on thecenter rod 154′.

Referring now to FIGS. 1 and 4, the shell assembly 31 will be discussedin detail. The shell assembly 31 includes a shell 182, a pusher back186, a cylindrical knife 188, and a fastener guide 192. The shell 182has an outer housing portion 194 defining a throughbore 198, andincludes a distal cylindrical section 200, a central conical section 202and a proximal cylindrical section 204. A plurality of openings 206 areformed in the conical section 202 that are configured and dimensioned topermit the passage of fluid and tissue therethrough during use of thestapling device 10 (FIG. 1). A pair of flexible engagement members 207are formed on the proximal cylindrical section 204 of the shell 182. Asillustrated, the engagement members 207 are positioned in diametricalopposition. However, alternative configurations for the engagementmembers 207 are also contemplated. The engagement members 207 arepositioned within openings 207A formed on the distal end of the outertube 14A to secure the shell 182 to the elongated body 14. A pair ofopenings 211 are formed in the proximal end of outer tube 14A, only oneof which is shown, that are configured and dimensioned to receiveprotrusions (not shown) formed on the internal wall of the stationaryhandle 18 to facilitate attachment of the outer tube 14A to the handleportion 12.

The pusher back 186 is slidably positioned within the shell 182, andincludes a throughbore 208A, a distal cylindrical section 210 that isconfigured and dimensioned for slidable reception by the distalcylindrical section 200 of the shell 182, a central conical section 212,a proximal cylindrical section 214, and a receptacle 215 (FIG. 14) toreceive excised tissue. The receptacle 215 is configured to define adepth substantially within the range of approximately 0.275 cm(approximately 0.75 inches) to approximately 0.79 cm (approximately 2.0inches). For example, in one embodiment, the receptacle 215 isconfigured to define a depth of approximately 0.52 cm (approximately1.33 inches).

Referring again to FIG. 4, the cylindrical knife 188 is retained withinthe throughbore 208A of the pusher back 186 to fixedly the secure knife188 in relation to the pusher 190. The knife 188 may be retained withinthe pusher back 186 in any suitable manner, including but not limited tothe use of adhesives, crimping, pins, a friction fit, etc.

As mentioned earlier, the pusher back 186 includes the aforementionedmembers 220, which are configured to securely engage the resilientfingers 110 of the pusher link 74. Engagement of the members 220 and thefingers 110 fastens the pusher link 74 to the pusher back 186 such thata distal face of the pusher link 74 abuts a proximal face of the pusherback 186. At a distal end, the pusher back 186 includes a pusher 190incorporating a plurality of distally extending fingers 226 that areslidably positioned within the fastener receiving slots 228 formed inthe fastener guide 192 to eject the fasteners 230.

With reference to FIG. 17, the slots 228 (see also FIG. 4) formed in thefastener guide 192 will be described. In one illustrative embodiment,the slots 228 each have a first sidewall 228A, a second sidewall 228B,and a pair of substantially rectangular recesses 228C, 228D that arepositioned at opposite ends of the respective first and second sidewalls228A, 228B. The first sidewall 228A is substantially convex, andincludes a first end that is connected to the recess 228C, and a secondend that is connected to the recess 228D. The second sidewall 228Bincludes a sidewall portion 228E with a longitudinal axis that isparallel to the longitudinal axis of the slot 228, and a pair of angledsidewall portions 228F. Each angled sidewall portion 228F interconnectsone end of the sidewall portion 228E with one of recesses 228C, 228D.Each of the recess 228C, 228D is configured and dimensioned tofrictionally retain a leg of the fasteners 230 (FIG. 14) therein. Itshould be appreciated that the configuration of the slots 228 may bealtered or varied in alternative embodiments of the present disclosure.

Returning now to FIG. 4, during use of the stapling device 10, when thepusher link 74 is advanced distally in response to actuation of thefiring trigger 20 (FIG. 1), the pusher back 186 is advanced distallywithin the shell 182. Advancement of the pusher back 186 causescorresponding advancement of the fingers 226 provided on the pusher 190through the slots 228 of the fastener guide 192 to advance and eject thefasteners 230 from the fastener guide 192 into the fastener deformingpockets 255 formed in the tissue contacting surface 252 of the anvil129. Since the knife 188 is secured to the pusher back 186, the knife188 is also advanced distally to cut tissue positioned between the anvilassembly 30 and the shell assembly 31.

The shell 182 further includes a rigid bushing 209 that is supported inthe proximal end of an inner guide portion 196 (FIG. 14). The rigidbushing 209 includes a throughbore 209A extending therethrough toslidably receive the anvil retainer 38 and the center rod of the anvilassembly 30. The bushing 209 provides lateral support for the flexiblefingers 272 (FIG. 3) of the anvil retainer 38 upon approximation of theanvil assembly 30 to inhibit disengagement of the anvil assembly 30 fromthe anvil retainer 38. When the anvil assembly 30 is un-approximated,i.e., spaced apart from the shell assembly 31, the flexible fingers 272of the anvil retainer 38 are positioned externally of the bushing 209 topermit outward flexure of the flexible fingers 272 to facilitate removalof the anvil assembly 30 from the anvil retainer 38.

With reference to FIGS. 2 and 18-20, a cam adjustment member 400 issecured by a set screw 312 onto a sidewall 306A of the screw stop 306.Specifically, the cam adjustment member 400 is positioned within arecess 306B formed in the sidewall 306A. The cam adjustment member 400includes a circular disc 402 having a throughbore 404 that iseccentrically formed through the disc 402, and dimensioned to receivethe set screw 312. A smaller notch, or hole 406 is also formed in thedisc 402, and is dimensioned to receive a tip of an adjustment tool (notshown). The recess 306B includes a forward abutment surface 306C and arear abutment surface 306D, and is dimensioned to receive the disc 402such that the outer edge of the disc 402 abuts the respective forwardand rear abutment surfaces 306C, 306D. The set screw 312 extends throughthe disc 402 and the screw stop 306 upon assembly.

The cam adjustment member 400 allows for the axial position of the screwstop 306 on the screw 32 to be adjusted, and thus, for adjustment of theair gap defined between the shell assembly 31 and the anvil assembly 30during manufacture. More specifically, loosening of the set screw 312allows the disc 402 to rotate within the recess 306B of the screw stop306 while still remaining fixed to the screw 32. Since the disc 402 iseccentrically mounted about the set screw 312, and is in engagement withthe respective forward and rear abutment surfaces 306C, 306D of therecess 306B, rotation of the disc 402 about the fixed set screw 312urges the screw stop 306 axially along the screw 32 to adjust the axialposition of the screw stop 306 on the screw 32. For example, when thedisc 402 is rotated clockwise, i.e., in the direction identified byarrow “B” in FIG. 19, the screw stop 306 will be moved axially inrelation to the screw 32 in the direction indicated by arrow “C” inresponse to engagement between the outer edge of the disc 402 and therear abutment surface 306D of the recess 306B. Conversely, when the disc402 is rotated counter-clockwise, i.e., in the direction indicated byarrow “D” in FIG. 18, the screw stop 306 will be moved axially inrelation to the screw 32 in the direction indicated by arrow “E” inresponse to engagement between the outer edge of the disc 402 and theforward abutment surface 306C of the recess 306B.

In an alternative embodiment, the circular disc 402 may be replaced withthe rectangular member 402′ shown in FIG. 21A or 21B, which presets thesize of the air gap defined between the shell assembly 31 and the anvilassembly 30, and does not provide for adjustment of the screw stop 306on the screw 32. The rectangular member 402′ includes an opening 404′that is configured and dimensioned to receive the set screw 302 of FIG.2 to properly locate the screw stop 306 on the screw 32. The position ofthe opening 404′ on the rectangular member 402′ is selected to providethe appropriate size air gap for a particular size fastener, and willvary depending on the particular size fastener, e.g., 3.5 mm or 4.8 mmfasteners, that is housed in the shell assembly 31. The rectangularmember 402′ includes one or more notches 406′ to identify duringmanufacture the appropriate rectangular member 404′ to use for the sizefasteners loaded in the stapling device to ensure setting of theappropriate size air gap.

With reference now to FIGS. 1, 2, 22, and 23, the stapling device 10 mayfurther incorporate an indicator mechanism that provides the clinicianwith an indication that the stapling device 10 has not beenapproximated, and is not in a fire-ready condition. The indicatormechanism includes the aforementioned indicator 24, as well as a lenscover 24A, and a slide member 500. The indicator is described in detailin U.S. Pat. No. 7,303,106, the entire contents of which areincorporated herein by reference.

The indicator 24 includes indicia providing the clinician withinformation regarding whether or not the stapling device 10 is read tofire, and is pivotally supported about a pivot member 502. It isenvisioned that the pivot member 502 may be formed monolithically withthe handle sections 19A, 19B of the stapling device 10. The lens cover24 a is positioned above the indicator 24, and may be includemagnification material to facilitate visualization of the indicator 24.

The slide member 500 of the indicator mechanism includes a body portion504 having an elongated slot 506 formed therein, a distal abutmentmember or upturned lip portion 508, and a proximal extension 510. Theslide member 500 is slidably positioned between the handle sections 19A,19B of the device 10, and the proximal extension 510 is slidablysupported within the stationary handle 18 by support structure 516. Abiasing member 512, e.g., a coil spring, is positioned in compressionabout the proximal extension 510 between the support structure 516 andthe body portion 504 of the slide member 500 to urge the slide member500 distally within the stationary handle 18.

The indicator 24 includes a pair of downwardly extending projections518, 520 that are positioned about the pivot member 502. The upturnedlip portion 508 of slide member 500 is positioned between theprojections 518, 520, and is positioned to engage the projections 518,520 as the slide member 500 moves within the stationary handle 18. Whenthe stapling device 10 is in an unfired position, the biasing member 512urges the slide member 500 distally to move the lip portion 508 intoengagement with the projection 518 to pivot the indicator 24 to a firstposition, which identifies that the stapling device 10 is not in afire-ready condition.

As discussed above, the screw stop 306 is fixedly attached to the screw32. The screw stop 306 includes a first engagement member 522 (FIG. 2)that is positioned to travel through the slot 506 formed in slide member500 (FIG. 22) and engage the proximal end 506A of the slot 506 duringapproximation of the stapling device 10. When the engagement member 522abuts the proximal end 506A of the slot 506, further approximation ofthe stapling device 10 moves the slide member 500 proximally within thestationary handle 18 against the bias of the spring 512 such that theupturned lip 508 of the slide member 500 engages the projections 518,520 of the indicator 24, as shown in FIG. 23. Engagement between theprojections 518, 520 and the lip 508 causes the indicator 24 to pivotabout the pivot member 502 to a second position, in which the indicator24 provides the clinician with an indication that the stapling device 10has been sufficiently approximated, and is ready for firing.

Referring now to FIGS. 2, 24 and 25, the firing-lockout mechanism willbe discussed. The firing lockout mechanism includes the aforementionedtrigger lock 26, as well as a lockout member 530. The trigger lock 26 ispivotally supported within bores 532 formed in the handle sections 19A,19B (FIG. 2), e.g., about a pivot member 534. The pivot member 534extends from an upper edge of the trigger lock 26, and is T-shaped suchthat the pivot member 534 frictionally engages an inner wall of thebores 532 to prevent free rotation of the trigger lock 26. The triggerlock 26 is positioned between abutments 89, 91 formed on the firingtrigger 20 to prevent actuation of the trigger 20 when the trigger lock26 is in a locked position.

The lockout member 530 (FIG. 24) includes a body portion 536, a proximalextension 538, a pair of front legs 540A, a pair of rear legs 540B, andan abutment member or downturned lip portion 542. The lockout member 530is slidably positioned between respective first and second stops 544 and546 (FIG. 23) formed on an internal wall of the handle sections 19A, 19B(FIG. 2). The stop 544 is configured, dimensioned, and positioned toengage the extension 538 of the lockout member 530, and the front legs540A of the lockout member 530. A biasing member 549 is positionedbetween the stop 544 and the rear legs 540B about the proximal extension538 to urge the lockout 530 to a distal-most position wherein the legs540A abut the stop 546. In this position, the extension 26B (FIG. 2) ofthe trigger lock 26 is positioned beneath the lip portion 542 of thelockout member 530 to prevent pivotal movement of the trigger lock 26,thus preventing actuation of the stapling device 10.

During use, when the anvil assembly 30 and the shell assembly 31 areapproximated, the screw 32 (FIG. 2) is moved proximally within thestationary handle 18, and one or more engagement members 548 formed onthe screw stop 306 abut the front legs 540A of the lockout member 530 tomove the lockout member 530 proximally against the bias of the member549 to a position in which the lip portion 542 is spaced proximally fromthe extension 26 b of the trigger lock 26. In this position of thelockout member 530, the trigger lock 526 can be pivoted to a positionthat does not obstruct operation of the trigger 20 such that thestapling device 10 can be fired.

With reference to FIGS. 25 and 26, the stapling device 10 may furtherinclude a tactile indicator mechanism. The tactile indicator mechanismis provided in stationary handle 18 (FIG. 1), and includes an abutmentmember 580 that is slidably positioned in a vertical slot 582 definedwithin the handle sections 19A, 19B. The abutment member 580 includes aprotuberance 580A, and a guide rib 580B. The protuberance 580A isconfigured and dimensioned to be received within one of two detents582A, 582B formed along a wall of the slot 582. The abutment member 580is movable from a retracted (downward) position, wherein theprotuberance 580A is positioned within the detent 582A, to an extended(upward) position, wherein the protuberance 580A is positioned withinthe detent 582B. Engagement between the protuberance 580A and the detent582A retains the abutment member 580 in the downward position, andengagement between the protuberance 580A and the detent 582B retains theabutment member 580 in the upward position. The vertical slot 582 mayfurther include a detent 582C that is configured, dimensioned, andpositioned to slidably receive guide the rib 580B, and thereby maintainthe abutment member 580 in contact with the slot 582.

Prior to firing of the stapling device 10, the abutment member 580 islocated in the retracted (downward) position. When the stapling device10 is fired, an extension 590 (FIG. 2) of the firing link 72 engages theabutment member 580, and moves the abutment member 580 from itsretracted to its extended position. In the extended position, theabutment member 580 extends into the channel 111 (FIG. 2) of thestationary handle 18.

The screw stop 306 further includes a pair of wings for slidableengagement with the channel 111 (FIG. 2) of the stationary handle 18.After the stapling device 10 has been fired, the abutment member 580(FIGS. 25, 26) is positioned within the channel 111. Duringunapproximation of the anvil assembly 30 and the shell assembly 31,after the anvil assembly 30 has been separated from the shell assembly31 by a distance sufficient to allow the anvil assembly 30 to be removedfrom the anvil retainer 38, one of the wings 584 of the screw stop 306engages the abutment member 580. This engagement between the abutmentmember 580 and the wing 584 of the screw stop 306 provides a tactileand/or an audible indication to the clinician that the anvil assembly 30can be removed or disengaged from the anvil retainer 38. If the surgicalstapling device 10 is un-approximated further, the wings 584 will forceabutment member 580 from the extended position back to the retractedposition.

As discussed above, the stapling device 10 is particularly suitable foruse in a surgical hemorrhoid procedure, although it can be used in otherprocedures. During such a procedure, an access port, such as the accessport 1300 shown in FIG. 27, may be inserted into the patient's anus tofacilitate access to the target tissue, e.g., prolapsed colon tissue, asseen in FIGS. 30-33. Next, the flexible member, such as the purse stringsuture “S” seen in FIG. 30, is placed into, above, or in the vicinity ofthe target tissue, and the anvil assembly 30 is inserted through theaccess port into the anus and rectum. The bulbous member 126 included onthe anvil head 124 allows for smooth passage of the anvil assembly 30through the body orifice, and past the purse string suture S.Thereafter, the purse string suture is inserted into one of theapertures 286A-286C formed in the center rod 154, as seen in FIGS. 34and 35.

Prior to attachment of the anvil assembly 30 and the anvil retainer 38,the stapling device 10 is in the un-approximated position. In thisposition, the biasing member 106 (FIG. 2) in engagement with thecoupling member 86 urges the pusher link 74 to its proximal-mostposition in which the coupling member 86 abuts the screw-stop 306, andthe biasing member 512 is in engagement with the slide member 500 (FIG.2) of the indicator mechanism to position the slide member 500 inengagement with the projection 518 (FIG. 23) of the indicator 24 topivot the indicator 24 in a clockwise direction, as viewed in FIGS. 2and 23. Additionally, the biasing member 549 (FIG. 23) is in engagementwith the body 536 of the lockout member 530 to urge the lockout member530 to its distal-most position, wherein the lip portion 542 of thelockout member 530 is positioned above the extension 26B (FIG. 2) of thetrigger lock 26 to prevent movement of the trigger lock 26 to theunlocked position. The biasing member 82A (FIG. 2) is also engaged withthe pivot member 79 to urge the pivot member 79 to the base of thevertical slot 82 formed between the handle sections 19A, 19B, and thetactile indicator 580 is in the retracted or downward position with theprotrusion 580A positioned with the detent 582A.

To attach the anvil assembly 30 to the anvil retainer 38, the center rod154 (FIGS. 8, 9) of the anvil assembly 30 is positioned within the anvilretainer 38 (FIGS. 1 and 5), and advanced proximally such that theannular protrusion 280 of the center rod 154 engages the flexiblefingers 272 of the anvil retainer 38. Upon engagement of the annularprotrusion 280 with the flexible fingers 272, the flexible fingers 272are forced outwardly, thereby facilitating engagement of the annularprotrusion 280 and the annular recess 282 of the anvil retainer 38 toinhibit relative longitudinal movement between the center rod 154 andthe anvil retainer 38.

Following attachment of the anvil assembly 30 and the anvil retainer 38(FIG. 1), the stapling device 10 can be moved into the approximatedposition. To do so, approximation knob 22 is rotated to move the anvilassembly 30 proximally towards the shell assembly 31 as rotation of theapproximation knob 22 causes corresponding rotation of the cylindricalsleeve 33, which thereby moves the pin 52 (FIG. 2) along the helicalchannel 50. Movement of the pin 52 along the helical channel 50 causesthe screw 32 to translate proximally within the sleeve 33. As the distalend of the screw 32 is operatively connected to the anvil retainer 38,retraction of the screw 32 within the sleeve 33 is translated intoproximal movement of the anvil retainer 38, and consequently, theconnected anvil assembly 30. During proximal movement of the anvilassembly 30, the target tissue is drawn into the shell assembly via theattachment between the suture “S” and the center rod 154 at theapertures 286A-286C. (FIGS. 35, 36)

Since the screw stop 306 is connected to the screw 32 by the set screw312 (FIG. 2), retraction of the screw 32 within sleeve 33 causes thescrew stop 306 to move from a distal position within the stationaryhandle 18 to a proximal position. During this movement, the firstengagement member 522 formed on the screw stop 306 abuts the proximalend 506 a of the slot 506 of the slide plate 500, and moves the slideplate 500 proximally against the bias of the spring 512. As the slideplate 500 moves proximally, the lip 508 of the slide member 500 engagesthe projection 520 (FIG. 23) on the indicator 24 to pivot the indicator24 in a counter-clockwise direction, as viewed in FIGS. 2 and 23.

As the screw stop 306 is moved from the distal position to the proximalposition, the second engagement member(s) 548 (FIG. 20) of the screwstop 306 come into engagement with the distal legs 540A (FIG. 24) of thelockout member 530 to move the lockout member 530 proximally to aposition in which the lip portion 542 is spaced proximally from theextension 26B (FIG. 2) of the trigger lock 26. In this position, thetrigger lock 26 can be pivoted to an unlocked position to permit firingof the stapling device 10.

As the screw stop 306 is moved into its proximal-most position withinthe stationary handle 18, the abutment surface 307 of the screw stop 306is positioned to engage the pivot member 79 (FIG. 2) of the firing link72. The abutment surface 307 engages the pivot member 79 during firingof the stapling device 10, and acts as a backstop for the pivot member79.

During firing of the surgical stapling device 10, as the trigger 20 iscompressed towards the stationary handle 18, the pivot member 79 (FIG.2) engages the abutment surface 307 (FIG. 18) on the screw stop 306, andthe firing trigger 20 is pushed distally. Since the distal end of thefiring trigger 22 is connected to the proximal end of pusher link 74through the coupling member 86, distal movement of the firing trigger 20causes corresponding movement of the pusher link 74 to effectuateadvancement of the pusher back 186 (FIG. 4) within the shell assembly 31(FIG. 1). As the pusher back 186 is advanced within the shell assembly31, the fingers 190 (FIG. 4) engage and eject the fasteners 230 (FIGS. 4and 14) from the fastener guide 192. The knife 188 moves concurrentlywith pusher back 186 into engagement with the cutting ring 128 (FIG. 10)to thereby sever tissue “H” positioned between the anvil assembly 30 andthe shell assembly 31, as seen in FIG. 36

As the trigger 20 is actuated, i.e., compressed towards the stationaryhandle 18, the extension 590 (FIG. 2) of the firing link 72 is pivotedtowards, and into engagement with, the abutment member 580 (FIGS. 25,26) to move the abutment member 580 from the retracted position to theextended position. In the extended position, the abutment member 580obstructs the channel 111 formed in the stationary handle 18.

After firing of the device, the anvil assembly 30 (FIG. 1) is separatedfrom the shell assembly 31. As the anvil assembly 30 is moved distally,the wings 584 (FIGS. 2, 20) of the screw stop 306 engage the tactileindicator 580 (FIG. 25), which thereby provides the clinician with atactile and/or audible indication that center rod 154 (FIGS. 8, 19) canbe disengaged from the anvil retainer 38 (FIG. 10).

FIGS. 12 and 12A illustrate an alternate embodiment of the surgicalstapler of the present disclosure, designated generally by referencenumeral 110. Stapler 110 includes a handle assembly 112, a central bodyportion 114 and a shell assembly 120. Surgical stapler 110 is identicalto stapler 10 of FIG. 1 except for the alignment pins and shell assemblyreceiving holes described below and thus the internal components are notshown or described.

Anvil head 166 has a plurality of projections shown in the form ofalignment pins 171 engagable with alignment holes 121 in the shellassembly 120. The pins or projections 171 extend proximally from theanvil head 166 and function to help align the anvil 166 and shellassembly 120 and to limit axial movement of the anvil head, especiallyin the instance where a relatively long anvil shaft is provided such asin hemorrhoid staplers. It should be appreciated that the alignment pinscan also be utilized in other circular staplers. The pins 171 can havetapered ends 173 as shown in FIG. 12A.

The pins function to limit movement of the anvil head 166 with respectto the shell assembly 120. In one embodiment, the pins have an outerdimension substantially equal to the inner diameter of the alignmentholes of the shell assembly 120 to frictionally fit within the alignmentholes with sufficient force for retention, while not inhibitingre-approximation of the anvil assembly. In other embodiments, the pinscan have a smaller outer dimension in relation to the inner diameter ofthe alignment holes to thereby more loosely be seated in the alignmentholes, while still functioning to limit axial movement and rotationalmovement of the anvil head. The pins 171 are preferably inboard(radially inward) of the circular knife and the staple rows of thestapler 110. Two or more pins substantially equally radially spaced areprovided in the illustrated embodiment. The pins can be spaced atintervals other than the approximately 180 degrees shown. Although thepins are shown with an anvil shaft 164 having through holes 175 for apurse string suture, the pins can be used with other anvil shafts.

With reference now to FIGS. 27 and 28, an anoscope kit 1000 isillustrated for use with the aforedescribed stapling device 10 (FIG. 1).The anoscope kit 1000 facilitates access to internal tissue during thecourse of a surgical procedure. For example, during the followingdiscussion, the anoscope kit 1000 and the stapling device 10 will bediscussed in the context of a surgical hemorrhoidal procedure, whereinhemorrhoidal tissue “H” (FIG. 35) is removed from a patient's analcanal. Note the stapling device 10 disclosed herein can be used withother anoscope kits or with other ports, or inserted directly into thebody opening.

The anoscope kit 1000 includes an obturator 1100 with a dilating tip1102, an anoscope 1200, and a port 1300. In one embodiment of theanoscope kit 1000, it is envisioned that the anoscope 1200 and the port1300 may be composed of a clear material, e.g., polycarbonate, tofacilitate the visualization of target tissue, as well as any adjacentor surrounding tissue, during the surgical procedure. However,alternative materials of construction can also be utilized.

The anoscope 1200 includes a dished flange 1202, and a sleeve 1204 thatextends along a longitudinal axis “X.” The flange 1202 extends from aproximal end 1206 of the sleeve 1204, and includes a first pair of wings1208 that extend radially outwardly therefrom relative to thelongitudinal axis “X.” The wings 1208 are configured and dimensioned formanual engagement by the clinician to facilitate manipulation of theanoscope 1200 during the course of the surgical hemorrhoidal procedure.The wings 1208 preferably include a substantially uniform proximalsurface 1210, however it could alternatively include a textured surface.

The sleeve 1204 of the anoscope 1200 extends distally from the flange1202, and defines an internal dimension that allows for removablereception of the obturator 1100. The sleeve 1204 includes asubstantially conical distal tip 1212 to facilitate the dilation oftissue, e.g., the patient's anal canal, and thus, insertion of theanoscope 1200, as well as rotation of the anoscope 1200 once positionedinternally.

To assist in placement of purse strings, the sleeve 1204 may includemarkings 1222. When included, the markings 1222 facilitate the placementof purse strings at a constant depth within the anal canal.

The sleeve 1204 further includes an open region 1214 that extendslongitudinally therethrough along the axis “X,” and a bridge 1216 thatspans the open region 1214, thereby dividing the open region 1214 intorespective proximal and distal openings 1218, 1220. It is envisionedthat the bridge 1216 may extend across the sleeve 1204 to define any arcof suitable dimensions. For example, it is envisioned that the arcdefined by the bridge 1216 may be less than 180°. However, an arcgreater than 180° is also contemplated.

The configuration of the bridge 1216 may be altered or varied inalterative embodiments to realize any suitable axial length. In oneparticular embodiment, the bridge 1216 defines an axial length of about1.5 cm (approximately 0.59 inches), and is positioned such thatrespective proximal and distal ends 1216A, 1216B of the bridge 1216 arerespectively located about 3 cm (approximately 1.18 inches) and about4.5 cm (approximately 1.77 inches) from the proximal end 1206 of thesleeve 1204, i.e., from the point where the flange 1202 extends radiallyfrom the sleeve 1204. In this embodiment, upon insertion of the anoscope1200 into the patient's anal canal, the distal opening 1220 will bepositioned above the dentate line, which is located in the human analcanal about 2 cm (approximately 0.78 inches) from the anus, so thatpurse stringing, and subsequent tissue removal, e.g., by the staplingdevice 10 of FIG. 1, will also occur above the dentate line.

The port component 1300 of the anoscope kit 1000 defines an internaldimension that allows for removable reception of the anoscope 1200, andincludes a pair of wings 1302 that extend outwardly therefrom relativeto the longitudinal axis “X”. The wings 1302 are configured anddimensioned for manual engagement by the clinician to facilitatehandling and manipulation of the port 1300 during the course of thehemorrhoid procedure. To facilitate fixation of the port 1300, the wings1302 may include a pair of apertures 1304 that are configured anddimensioned to receive a flexible member (not shown), such as a suture,that can be secured to the patient's tissue.

With reference now to FIGS. 29-37 as well, the use and operation of theanoscope kit 1000 in connection with the stapling device 10 of FIG. 1will now be discussed. Prior to insertion, the anoscope kit 1000 isassembled as illustrated in FIG. 28. Specifically, the anoscope 1200 ispositioned coaxially within the port 1300, and the obturator 1100 ispositioned coaxially within the sleeve 1204 of the anoscope 1200. Theassembled anoscope kit 1000 is then inserted transanally into a patient(FIG. 29) such that the bridge 1216 is positioned above the dentateline. Thereafter, the obturator 1100 is removed, leaving the anoscope1200 positioned within port 1300, which extends from the patient's anus(FIG. 30). Either prior or subsequent to assembly of the anoscope kit1000, the port 1300 may be optionally fixed to the patient's tissue bythe aforementioned flexible member (not shown). To reiterate, theflexible member (e.g. suture) can be positioned within the apertures1304 included on the wings 1302 of the port 1300, and can be thereaftersecured to the patient.

As seen in FIGS. 31-33, following removal of the obturator 1100, thetarget tissue, such as internal hemorrhoidal tissue “H” (FIG. 35), isreceived by the distal opening 1220 (FIGS. 27, 30) in the sleeve 1204such that the tissue is positioned within the sleeve 1204 of theanoscope 1200. The clinician then attaches a length of suture “S” to thetarget tissue “H,” a procedure referred to generally as “pursestringing.” Thereafter, the anoscope 1200 (FIG. 27) can be rotatedwithin the port 1300 to one or more subsequent positions, exemplified inthe transition between FIGS. 31, 32, and 33, such that additionalinternal hemorrhoidal tissue, if any, can be received within the distalopening 1220 (FIGS. 27, 30) and sutured, or purse stringed.

After purse stringing is completed, the anoscope 1200 (FIG. 27) isremoved from the patient's anus. The anvil assembly 30 of the staplingdevice 10 of FIG. 1 is then inserted into the patient's anal cavity, andthe two ends of the suture “S” are passed through one of the apertures286A-286C formed in the center rod 154, as shown in FIG. 34, dependentupon the amount of tissue the clinician wishes to draw into the shellassembly 31. The length of the suture “S” is such that the suture “S”extends from the port 1300 after positioning within the apertures286A-286C (FIG. 34).

The anvil assembly 30 is then connected to the anvil retainer 38 (FIG.35) in the manner discussed above, and the approximation knob 22(FIG. 1) is rotated to move the anvil assembly 30 proximally, i.e.,towards, the shell assembly 31, such that the target tissue “H” ispositioned within the shell assembly 31,

The stapling device 10 is then fired to sever and fasten the targettissue “H.” After severing of the tissue “H,” the stapling device 10 canbe removed from the port 1300 with the tissue “H” positioned within theshell boss 31, as shown in FIG. 37.

While several embodiments of the disclosure have been shown in thedrawings and/or discussed herein, it is not intended that the disclosurebe limited thereto, as it is intended that the disclosure be as broad inscope as the art will allow and that the specification be read likewise.Therefore, the above description should not be construed as limiting,but merely as exemplifications of particular embodiments. Those skilledin the art will envision other modifications within the scope and spiritof the claims appended hereto.

The invention claimed is:
 1. A surgical fastener applying apparatuscomprising: an elongated body portion having proximal and distal ends;and a head portion disposed adjacent the distal end of the elongatedbody portion, the head portion comprising: a shell assembly defining acentral aperture and including an annular tissue contacting surface witha plurality of slots formed therein through which a plurality ofsurgical fasteners are ejected during firing of the surgical apparatus,the plurality of slots arranged in an annular configuration, the tissuecontacting surface having an opening formed therein spaced radially fromthe plurality of slots and spaced radially from the central aperture;and an anvil assembly movable in relation to the shell assembly, theanvil assembly including an annular tissue contacting surface, and aprojection extending proximally therefrom, the projection in alignmentwith the opening formed in the tissue contacting surface of the shellassembly, the projection being configured and dimensioned forpositioning within the opening formed in the tissue contacting surfaceof the shell assembly.
 2. The surgical apparatus according to claim 1,wherein the tissue contacting surface of the shell assembly includesfirst and second openings, and the tissue contacting surface of theanvil assembly includes first and second projections extendingproximally therefrom in alignment with the first and second openings. 3.The surgical apparatus according to claim 2, wherein the plurality ofopenings are spaced equidistant from one another, and the plurality ofprojections are spaced equidistant from one another.
 4. The surgicalapparatus according to claim 2, wherein the first and second openingsare positioned in diametrical opposition, and the first and secondprojections are positioned in diametrical opposition.
 5. The surgicalapparatus according to claim 1, wherein the opening is configured anddimensioned to frictionally receive the projection.
 6. The surgicalapparatus according to claim 1, wherein the projection includes atapered proximal end.
 7. The surgical apparatus according to claim 1,wherein the tissue contacting surface of the anvil assembly includes aplurality of pockets configured and dimensioned to receive the surgicalfasteners to facilitate formation thereof, the pockets arranged in anannular configuration.
 8. The surgical apparatus according to claim 1,wherein the opening is spaced radially inward from the plurality ofslots formed in the tissue contacting surface of the shell assembly withrespect to the central aperture.
 9. The surgical apparatus according toclaim 8, further including an annular cutting member movable in relationto the shell assembly, the projection being positioned radially inwardof the cutting member with respect to the central aperture of the shellassembly.
 10. The surgical apparatus according to claim 1, wherein theanvil assembly includes an anvil head, and an anvil shaft extendingproximally from the anvil head, wherein the projection extends inparallel relation to the anvil shaft.
 11. A method of performing asurgical procedure comprising: inserting an anvil assembly of a surgicalfastener applying apparatus into an opening in a patient; connecting theanvil assembly to a shell assembly of the surgical apparatus;approximating the anvil assembly and the shell assembly such that aprojection extending proximally from an annular tissue contactingsurface of the anvil assembly is inserted into a corresponding openingformed in an annular tissue contacting surface of the shell assembly inalignment with the projection, wherein the opening is spaced radiallyinward from a plurality of slots formed in the tissue contacting surfaceof the shell assembly and spaced radially outward from a centralaperture of the shell assembly; and firing the surgical apparatus toeject a plurality of surgical fasteners through the plurality of slotsformed in the tissue contacting surface of the shell assembly, and intotissue positioned between the anvil assembly and the shell assembly. 12.The method according to claim 11, wherein approximating the anvilassembly and the shell assembly includes inserting the projection intothe opening such that the projection is frictionally received by theopening.
 13. The method according to claim 12, wherein approximating theanvil assembly and the shell assembly includes inserting a plurality ofprojections extending proximally from the tissue contacting surface ofthe anvil assembly into a corresponding plurality of openings formed inthe tissue contacting surface of the shell assembly.
 14. The methodaccording to claim 11, wherein approximating the anvil assembly and theshell assembly includes inserting a first projection extendingproximally from the tissue contacting surface of the anvil assembly intoa first opening formed in the tissue contacting surface of the shellassembly, and inserting a second projection extending proximally fromthe tissue contacting surface of the anvil assembly into a secondopening formed in the tissue contacting surface of the shell assembly.15. The method according to claim 11, wherein approximating the anvilassembly and the shell assembly includes inserting a tapered proximalend of the projection into the opening.
 16. The method according toclaim 11, wherein firing the surgical apparatus includes advancing anannular cutting member distally in relation to the shell assembly tosever the tissue positioned between the anvil assembly and the shellassembly, wherein the projection is positioned radially inward of thecutting member with respect to the central aperture of the shellassembly.